/**
 * Copyright (c) 2007-2008 Nearchos Paspallis
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
/**
 * AspectSense
 *
 * Middleware for annotation-based, context-aware and adaptive services for
 * mobile and ubiquitous computing
 *
 * This project is an open-source effort, initiated by Nearchos Paspallis as
 * part of his PhD work at the University of Cyprus (http://www.ucy.ac.cy).
 *
 * More information about the project is available at "http://aspectsense.org".
 */

package org.aspectsense.graphs;

import java.util.HashSet;

/**
 * Immutable, empty implementation of the {@link Node} interface.
 *
 * @author Nearchos Paspallis [nearchos@cs.ucy.ac.cy]
 *         Date: Dec 21, 2007
 *         Time: 10:24:58 AM
 */
final public class DefaultNode<E> implements Node<E>
{
    private final E value;

    public DefaultNode(final E value)
    {
        super();

        this.value = value;
    }

    public E getValue()
    {
        return value;
    }

    public int hashCode()
    {
        return value.hashCode();
    }

    public boolean equals(Object object)
    {
        if(object == null) return false;

        if(this == object) return true;

        if(object.getClass() != this.getClass()) return false;

        final Node node = (Node) object;

        if(value == null)
        {
            return node.getValue() == null;
        }
        else
        {
            return value.equals(node.getValue());
        }
    }

    public String toString()
    {
        return value == null ? super.toString() : value.toString();
    }
}